membership plugin custom account form no longer working

I have a custom membership account form that until the most recent version of membership (3.4.5) was working just fine. I changed it by defining "MEMBERSHIP_ACCOUNT_FORM". I've confirmed the path to the custom form is working. When I go to the account page as defined in Membership Options / Membership Pages the page is blank. I've since reverted back to 3.4.4 since it's a production site and works there. Can you confirm that defining MEMBERSHIP_ACCOUNT_FORM is still the correct way to use a custom account form? If not, what should I be doing for the newest version of membership?